Active matrix organic electroluminescent display device and method of fabricating the same

Abstract

An organic electroluminescent display device includes a substrate, a gate line on the substrate, a data line crossing the gate line over the substrate, a switching thin film transistor near the crossing of the gate line and data line, a driving thin film transistor system including a plurality of sub-TFTs connected in parallel to the switching thin film transistor via a gate base, a power line crossing the gate line over the substrate and electrically connected with the plurality of sub-TFTs, a first electrode over the driving thin film transistor system in contact with the plurality of sub-TFTs, an organic electroluminescent layer on the first electrode, and a second electrode of transparent material on the organic electroluminescent layer.

1. An organic electroluminescent display device, comprising:
 a first substrate; 
 a gate line on the first substrate; 
 a data line crossing the gate line over the first substrate; 
 a switching thin film transistor near the crossing of the gate line and data line; 
 a driving thin film transistor system including a plurality of sub-TFTs connected in parallel to the switching thin film transistor via a gate base; 
 a power line crossing the gate line over the first substrate and electrically connected with the plurality of sub-TFTs; 
 an organic electroluminescent diode on a second substrate; and 
 a connection pattern between the first and second substrates, the connection pattern electrically connecting the driving thin film transistor system to the organic electroluminescent diode, 
 wherein the driving thin film transistor system includes first to fourth sub-TFTs having first to fourth driving gate electrodes, first to fourth driving source electrodes, first to fourth driving drain electrodes, and first to fourth active layers, 
 wherein the first driving drain electrode and the second driving drain electrode include a first united body, and the third driving drain electrode and the fourth driving drain electrode include a second united body, and 
 wherein the connection pattern contacts at least one middle of the first and second united bodies. 
 
     
     
       2. The device according to  claim 1 , wherein the organic electroluminescent diode includes a first electrode of transparent material on the second substrate, an organic electroluminescent layer on the first electrode, and a second electrode on the organic electroluminescent layer. 
     
     
       3. The device according to  claim 2 , wherein the organic electroluminescent layer includes a first carrier-transporting layer, an organic emission layer, and a second carrier-transporting layer. 
     
     
       4. The device according to  claim 1 , wherein the switching thin film transistor includes a switching gate electrode extending from the gate line, a switching source electrode extending from the data line, a switching drain electrode spaced apart from the switching source electrode, and a switching active layer between the switching gate electrode and the switching source and drain electrodes. 
     
     
       5. The device according to  claim 4 , wherein the switching drain electrode of the switching thin film transistor is connected to the gate base. 
     
     
       6. The device according to  claim 1 , wherein the first to fourth driving gate electrodes are connected to the gate base to electrically connect the driving thin film transistor system to the switching thin film transistor. 
     
     
       7. The device according to  claim 1 , wherein the second driving source electrode and the third driving source electrode include united body. 
     
     
       8. The device according to  claim 1 , wherein each of the first to fourth driving drain electrodes is spaced apart from each of the first to fourth driving source electrodes. 
     
     
       9. The device according to  claim 7 , further comprising power electrodes extending from the power line over the first to fourth driving source electrodes and electrically connected with the first to fourth source electrodes. 
     
     
       10. The device according to  claim 9 , wherein a first power electrode contacts the first driving source electrode, wherein a second power electrode contacts a middle of the united body of the second and third driving source electrodes, and wherein a third power electrode contacts the fourth driving source electrode.